The present invention relates to a row feeder for successively distributing nuts, as mechanical parts, from a delivery source to a plurality of nut attaching apparatuses such as nut welders or self-piercing nut assembling apparatuses.
There are widely used a number of weldable nuts or the so-called self-piercing nuts, and they are usually affixed to metal plates such as those which are typically incorporated motor vehicles. The self-piecing nut has an end face serving as a punch against the metal plate, thereby causing the nut to punch an installation aperture in the metal plate and to simultaneously fix the nut in place on the plate. In order to automate the nut attaching operation, the nut supplying apparatuses widely employ the so-called vibrating feeder.
When one automatic nut feeder successively supplies the nuts to one nut welder, a high capacity of the nut feeder is not fully utilized because the operation speed of the nut feeder is several times or several tens times as high as that of the nut welder.
The popular self-piercing nuts (hereinafter `nut`) are applied to various metal plates, typically to those which construct a motor vehicle body. It is a usual practice to attach in a one shot operation many such nuts to one metal plate as a workpiece, which in many cases is subjected at the same time to the punching, blanking, trimming and/or partial drawing processes. Generally, several sets of the nut assembling apparatuses are built in one press together with its main molds or parts. Any passage through which the nuts are fed to such self-piecing nut assembling apparatuses must not interfere with any punching dies or the like in the press. Thus, nut feeders are equipped in the vicinity of the press so as to deliver the nuts through flexible chute hoses to the respective nut assembling apparatuses. Due to a number of such apparatuses in one press, many chute hoses have to extend into the press and each of many nut feeders disposed near it must comprise a transfer device for causing the nuts to be supplied into the flexible chute hose. As a result, not only usual inspection and maintenance for changing or checking a press mold and/or maintenance work thereof but also operations for loading and unloading the press with a workpiece are rendered intricate. Further, the connecting and disconnecting of the chute hoses from the press are likewise made complicated, while other operations and the operator's movement around the press is difficult. In addition, since an automatic mold exchanger, in recently proposed large-scaled presses usually takes too much space, very little space is left for the nut feeders. It is very difficult and has been regarded as almost impossible to automate the connection and disconnection of a number of the chute hoses to and from the press mold.